U.S. patent application number 12/500436 was filed with the patent office on 2010-01-14 for needle for subcutaneous port.
Invention is credited to David A. Loiterman, Michael G. Loiterman.
Application Number | 20100010413 12/500436 |
Document ID | / |
Family ID | 41505811 |
Filed Date | 2010-01-14 |
United States Patent
Application |
20100010413 |
Kind Code |
A1 |
Loiterman; David A. ; et
al. |
January 14, 2010 |
Needle for Subcutaneous Port
Abstract
This disclosure relates to a new type of needed for a
subcutaneous port or for any use where blood is recycled, and more
precisely to a needle with reduced friction openings for easing
blood and its elements along a passageway made of a through bore in
the body of a needle. The needle includes an oval shape opening for
increased mechanical resistance of the needle while allowing a
greater passage curvature of the blood cells at the greatest zone
of passage. In other embodiments, a plurality of staggered openings
is used to reduce the flow through any single opening where damage
occurs, the openings can be made in a curved area, or a plurality
of smaller openings or a grid made of openings can be used to
further reduce the interference of the needle tip and the needle
openings on blood.
Inventors: |
Loiterman; David A.; (Oak
Brook, IL) ; Loiterman; Michael G.; (Yorkville,
IL) |
Correspondence
Address: |
VEDDER PRICE P.C.
222 N. LASALLE STREET
CHICAGO
IL
60601
US
|
Family ID: |
41505811 |
Appl. No.: |
12/500436 |
Filed: |
July 9, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61079238 |
Jul 9, 2008 |
|
|
|
61091044 |
Aug 22, 2008 |
|
|
|
Current U.S.
Class: |
604/6.16 ;
604/266; 604/272 |
Current CPC
Class: |
A61M 39/0208 20130101;
A61M 1/3661 20140204; A61M 5/329 20130101; A61M 5/3291 20130101;
A61M 2206/11 20130101; A61M 5/3286 20130101; A61M 2005/1581
20130101 |
Class at
Publication: |
604/6.16 ;
604/272; 604/266 |
International
Class: |
A61M 5/00 20060101
A61M005/00; A61M 1/14 20060101 A61M001/14 |
Claims
1. A needle for a subcutaneous port adapted to reduce the damage to
a biological or physiological fluid at the inlet of the needle,
comprising: a needle shaft with a bore along a longitudinal axis of
the needle shaft and a proximal end and a distal end in opposition
thereof; a pointed tip at the distal end with a pointed end tip for
the entry of at least a portion of the needle shaft into a
biological or physiological fluid reservoir in the subcutaneous
port; and at least an inlet orifice along the needle shaft between
the proximal end and the distal end and in fluidic contact with the
biological or physiological fluid reservoir and adjacent to the
pointed tip, wherein said inlet orifice communicates with the bore
for the passage of the fluid from the biological or physiological
fluid reservoir through the inlet orifice and through the bore, and
wherein the inlet orifice has at least a rounded edge.
2. The needle of claim 1, wherein the inlet orifice is of oval
shape.
3. The needle of claim 2, wherein the oval shape has a long axe
along the longitudinal axis.
4. The needle of claim 3, wherein the pointed end tip at the
pointed tip is a 20 degree cone.
5. The needle of claim 1, wherein the needle shaft has an exterior
diameter in the range of 0.0645 to 0.0655 inch, and a bore of an
internal diameter in the range of 0.0525 inch to 0.0545 inch.
6. The needle of claim 1, wherein the needle shaft has a thickness
in the range of 0.001 to 0.003 inch.
7. The needle of claim 1, wherein the inlet orifice is a circular
opening with a diameter in the range of 0.042 inch and is offset
from the pointed end tip by approximately 0.035 inch.
8. The needle of claim 1, wherein at least two inlet orifices are
along the needle shaft between the primal end and the distal end
and in fluidic contact with the biological or physiological fluid
reservoir and adjacent to the pointed tip, wherein each of the at
least two inlet orifices communicate with the bore for the passage
of the biological or physiological fluid from the biological or
physiological fluid reservoir through the inlet orifice and through
the bore, and wherein the inlet orifice has at least a rounded
edge, and wherein each of the at least two inlet orifices are
staggered at approximately 180 degree along the needle shaft.
9. The needle of claim 8, wherein the needle shaft wherein the
longitudinal axis of is curved adjacent to the pointed tip.
10. The needle of claim 1, wherein a plurality of orifices are
along the needle shaft between the proximal end and the distal end
and in fluidic contact with the biological or physiological fluid
reservoir and adjacent to the pointed tip, and wherein each of the
plurality of inlet orifices communicate with the bore for the
passage of fluid from the biological or physiological fluid
reservoir through the inlet orifice and through the bore.
11. The needle of claim 10, wherein the plurality of orifices is a
mesh.
12. The needle of claim 1, wherein a surface of the bore is coated
with an anti-clotting.
13. The needle of claim 12, wherein the anti-clotting is
heparin.
14. The needle of claim 1, wherein a surface of the bore includes a
bio-compatible coating selected from a group consisting of polished
titanium oxide, and polymer coating.
15. The needle of claim 14, wherein the polymer coating is selected
from a group consisting of Teflon or PTFE.
16. The needle of claim 1, wherein an external surface of the
needle shaft is coated with an anti-clotting.
17. A method of protecting blood cells from damage during a medical
treatment with a subcutaneous port, where blood is circulated
through a needle, the method comprising the steps of: connecting a
needle to a medical treatment device for conducting a treatment
using multiple circulation of blood through the needle, the needle
having a needle shaft having a bore along a longitudinal axis of
the needle shaft and a proximal end and a distal end in opposition
thereof, a pointed tip at the distal end with a pointed end tip,
and at least an inlet orifice along the needle shaft between the
proximal end and the distal end, and wherein the inlet orifice has
at least a rounded edge for the protection of blood cells;
puncturing a plenum surface of a subcutaneous port for entry of at
least a portion of the needle shaft and the inlet orifice into a
fluid reservoir in the subcutaneous port; placing the inlet orifice
in fluidic contact with blood in the fluid reservoir for the
passage of the blood from the fluid reservoir through the inlet
orifice and through the bore; and circulating the blood so the flow
of blood circulates around the rounded edge to protect the blood
cells during the circulation to the medical treatment device.
18. The method of claim 17, wherein the medical treatment is
hemodialysis.
19. The method of claim 17, wherein a diameter of the rounded edge
is at least 5 to 10 times the total cross-section of blood cells in
the blood.
20. The method of claim 17, wherein the inlet orifice is an oval
has a long axe along the longitudinal axis
21. The needle of claim 1, wherein the biological or physiological
fluid is blood.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims priority from and the
benefit of U.S. Provisional Patent Application No. 61/079,238,
filed Jul. 9, 2008, entitled Needle for Subcutaneous Port, which
prior application is hereby incorporated herein by reference, and
U.S. Provisional Patent Application No. 61/091,044, filed on Aug.
22, 2008, also entitled Needle for Subcutaneous Port, which is also
hereby incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates to a needle for use with a
subcutaneous port with a membrane, to minimize damage caused to
blood cells as a result of rapid circulation of blood at the tip of
the needle, and more particularly, to a needle for a subcutaneous
port with openings and edges capable of protecting blood cells via
a reduced local velocity, a reduced friction, and a controlled
direction of the flow.
BACKGROUND
[0003] During medical interventions, tubes or catheters are used in
a wide variety of applications in conjunction with different
medical devices. Small, hollow tubes are introduced within a
patient's body to remove bodily fluids, circulate them through
external equipment, or to provide access to bodily fluids for
equipment. These tubes are often equipped with end needles, also
called high flow and low resistance needles, that puncture and are
passed through a regenerating layer of skin or into a surface to
connect with an internal volume where the fluid is found. Even when
sharpened hollow tubes cut the skin or the surface, a rip is made
in the shape of a small circle around the periphery of the tube. As
a result, part of the surface is cut away or damaged. The removed
portion can also become a loose particle entering the fluid to be
collected. When punctured, skin also requires additional care and
attention to heal properly.
[0004] In 1952, U.S. Pat. No. 2,717,600 to Huber first described
what is now known in the art as the Huber needle. A hollow cylinder
is cut in the shape of a pointed knife where the center circular
opening is angled as part of the bladed surface. As a result, the
Huber needle creates a small, linear incision as it is inserted and
does not remove part of the skin into which it is inserted as long
as the medium is allowed to deform plastically around the external
body of the Huber needle. FIG. 1 illustrates several Huber needles
as contemplated by U.S. Pat. No. 2,717,600.
[0005] While Huber needles are designed to minimize the residual
trace, their heads are not optimized to limit the pressure drop
created in a fluid moving in the Huber needle. For example, in the
vicinity of the tip, blood is accelerated locally into a narrow tip
and enters the needle head around an edged rim before it must
change direction and travel alongside the needle stem. A blood cell
hitting the edge of the needle may be damaged. Therefore, a medical
device, such as a pump, connected ultimately to a Huber needle
requires more energy to operate than if no needle is placed at the
tip. Using a Huber needle also results in a need to increase the
power at the pump, and thus subject the blood to greater pressure
gradients and greater exit velocities as it travels through the
length of the needle.
[0006] Human blood, unlike a pure liquid, is a bodily fluid
composed of different types of cells suspended in a liquid called
blood plasma. These cells are fragile and can be damaged easily as
they travel up a needle, and more precisely as they enter the tip
of a needle. Blood plasma is 90% water and 10% dissolved proteins,
glucose, mineral ions, hormones, or different soluble gases such as
carbon dioxide. These parts constitute 55% of blood fluid. The
remainder of human blood is made of red blood cells and different
types of white blood cells, such as neutrophil, eosinophil,
basophil, lymphocyte, monocyte, and macrophage cells. The red and
white blood cells are not rigid entities floating in the plasma but
are viscous bodies having a good degree of flexibility. As the
distance between adjacent cells in the blood decreases, the blood
increases in viscosity. As the plasma changes consistency, the
blood viscosity also increases.
[0007] When viscosity of a fluid transported in a tube increases,
the force needed to move the fluid also increases since these
forces must compensate for contact friction with the internal
surface of the tube. Such increased force can result in damage to
the fluid. The average viscosity of blood at 37.degree. C. is
0.0027 Ns/m.sup.2. Many factors can change the viscosity of blood
over time, factors such as hemodialysis. As the blood is filtered
during dialysis, unwanted waste, generally a portion of the liquid
in the blood is removed. Accordingly, the remaining portion of the
blood is thickened (i.e., the cells grow closer) in the volume.
Plasma viscosity and whole blood viscosity rises with hemodialysis
with the degree of ultrafiltration (i.e., weight loss). See The
Effect of Hemodialysis on Whole Blood, Plasma and Erythrocyte
Viscosity by Wink J., Vaziri N D., Barker S., Hyatt J., and Ritchie
C., at Int. J. Artif. Organs., September 1988; 11(5):340-2.
[0008] If 5% of the volume of a patient's blood is removed during
hemodialysis, the Wink research approximates the increase in
viscosity of the blood by the same amount, or about 5%. Patients on
hemodialysis sit for long periods of time and may be connected to a
machine for up to 8 hours. Their blood can be circulated many times
through an artificial kidney. As a result, a large fraction of the
blood is removed and the blood is often thickened significantly.
Accordingly, the damage on the blood cells at the needle increases
as the dialysis time increases unless the needle is designed to
protect the blood. Multiple passages of blood at a needle tip, even
if damage is minimum for each single passage can result in
undesired side effects to the patient.
[0009] The average size of the erythrocyte disk in a red blood cell
is 6 to 8 .mu.m where 1 .mu.m corresponds to 1.times.10.sup.-6 m or
0.40.times.10.sup.-4 in. The average size of the different human
white blood cells ranges from 7 to 17 .mu.m for lymphocytes and
monocytes, respectively. Since about 50% of the volume of blood is
made of blood cells, the average distance between adjacent cells
can also be taken to be around 7 to 17 .mu.m (for a total
cross-section of 34 .mu.m corresponding to the sum of a cell and
the surrounding plasma). To better understand the dynamics at the
tip of a high flow/low resistance needle, an average needle opening
of 1 mm in size with an opening hole of about 0.75 mm in radius, or
750 .mu.m, is about 20 times the size of the cross-section of the
cell moving through the opening hole.
[0010] The dynamics of a flow of liquid in an opening differs from
the dynamics of a flow of particles through the same opening. For
example, sand in an hourglass must have a precise maximum ratio
over the size of the opening between the upper and lower cavity to
flow freely as a semi-liquid. When blood cells are pushed through
an opening having a radius of relative importance compared to the
size of the cells, these cells can be damaged if the passage is too
narrow, if the passage is too rapid or if the change in direction
is abrupt. In addition, the reduced section of the needle tip
increases locally the velocity of the cells at the opening, thereby
increasing the energy available to damage the cells when they come
into contact with the edge of the high flow/low resistance needle
opening.
[0011] If blood is moved too rapidly, moved repetitively past sharp
edges, or pressurized in a choked area of the needle tip, damage to
the blood can occur, which may lead to a plurality of unwanted
medical conditions. In the case of cyclical and repetitive blood
circulating conditions, such as the dialysis treatment of blood
where the fluid is passed repeated through a filtering machine,
different elements of the blood can be progressively damaged with
each passage.
[0012] U.S. Pat. No. 5,041,098 ("Loiterman et al."), which is
incorporated herein by reference and is a prior art device
co-invented by the inventor of the present disclosure, describes a
subcutaneous device used in the dialysis process that must be
accessed a plurality of times as the patient undergoes repetitive
treatments. The Huber needle described above, while adapted to
preserve the silicone-based plenum surface shown as element 20 of
FIG. 2 taken from Loiterman et al., results in the creation of a
needle only capable of drawing blood near the bottom of the
blood-filled cavity 14 at an angle from the bottom of the blood
flow in the cavity. The Huber needle is unsuited for this use.
[0013] In FIG. 2, Loiterman et al. teaches the use of a sharp
needle point with a cpointed tip and a lateral circular opening to
draw blood at a mid height of the cavity in a perpendicular flow.
In FIG. 3, Loiterman et al. shows the proportion of the size of the
needle compared to the blood cavity and illustrates how a bent tip
can be used to position the end portion of the needle within the
cavity 14. What is needed is a new type of needle designed for
repetitive use on an internal port for access of an external device
to the blood stream that can be inserted and withdrawn without
damage and that is capable of promoting undamaged flow of blood
after repetitive passages through the needle opening(s) when the
blood is circulated and changes consistency during the process of
circulation.
SUMMARY
[0014] This disclosure relates to a new type of needle for a
subcutaneous port or for any use where blood is recycled, and more
precisely to a needle with reduced friction openings for easing
blood and its elements along a passageway made of a through bore in
the body of a needle. The needle includes an oval shape opening for
increased mechanical resistance of the needle while allowing a
greater passage curvature of the blood cells at the greatest zone
of passage. In other embodiments, a plurality of staggered openings
is used to reduce the flow through any single opening where damage
occurs, the openings can be made in a curved area, or a plurality
of smaller openings or a grid made of openings can be used to
further reduce the interference of the needle tip on the blood.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Certain embodiments are shown in the drawings. However, it
is understood that the present disclosure is not limited to the
arrangements and instrumentality shown in the attached
drawings.
[0016] FIG. 1 is taken from the prior art and illustrates several
Huber syringe needles.
[0017] FIG. 2 is taken from the prior art and illustrates a port
with one type of known needle.
[0018] FIG. 3 is taken from the prior art and illustrates the port
of FIG. 2 shown three dimensionally with a bent needle.
[0019] FIG. 4 is a port from the prior art with a needle having an
oval opening according to a first embodiment of the present
disclosure.
[0020] FIG. 5A is a detailed front view of the needle of FIG.
4.
[0021] FIG. 5B is a detailed cut view of the needle of FIG. 5A
along cut line 5B-5B.
[0022] FIG. 6 is a port from the prior art with a needle with two
staggered openings according to another embodiment of the present
disclosure.
[0023] FIG. 7 is a port from the prior art with a bent needle
according to another embodiment of the present disclosure.
[0024] FIG. 8 is a port from the prior art with a needle with a
grid portion according to another embodiment of the present
disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0025] For the purposes of promoting and understanding the
principles disclosed herein, reference is now made to the preferred
embodiments illustrated in the drawings, and specific language is
used to describe the same. It is nevertheless understood that no
limitation of the scope of the invention is hereby intended. Such
alterations and further modifications in the illustrated devices
and such further applications of the principles disclosed and
illustrated herein are contemplated as would normally occur to one
skilled in the art to which this disclosure relates.
[0026] Needles are long, hollow tubes used when placed at one end
in a fluid such as a biologic or physiologic fluid to draw the said
fluid from the dipped end to the opposite end by applying a
pressure differential. Within the scope of this disclosure, the
word fluid includes any biologic or physiologic fluid such as, for
example, blood or urine. Needles have tips designed to puncture or
cut into a solid to reach a destination generally below the surface
where the fluid is found. The long axis of the needle contains a
hollow tubular channel (or through bore) extending from a proximal
end that may be connected to a machine or volume where fluid can be
stored. The distal end includes at least one or more orifices.
Orifices can be located at various distances along the body of the
needle and may be placed in different orientations.
[0027] Blood cells are damaged when they travel in the blood and
encounter an obstacle. Blood cells can also be damaged if the serum
in which they float is placed under a pressure differential that
results in the creation of shearing forces within a single blood
cell. For example, in a machine a pump can be used to suck blood
from a patient. If the needle is connected to a long tube, the
pressure at the pump must be sufficient to compensate the pressure
drop over the length of the tube. A powerful pump may result
locally in damage to the cells.
[0028] For damage to the blood to be minimized, the pressure drop
in the needle tip must be lowered. For example, keeping the blood
in a laminar flow while it enters and travels along the length of
the needle reduces the pressure drop compared to any turbulent flow
of blood. Another method of reducing the pressure loss through the
needle is to change the geometrical parameters of the opening or
the bore to prevent friction. For example, if the needle's internal
surface area is A, and opening area is a fraction of A, the speed
of the fluid through the opening will be a multiple of the speed in
the needle body. This change in velocity may result in turbulent
flow if the Reynolds number of the blood reaches a certain fixed
value based on fluid viscosity. In addition, the blood located in
the cavity or fluid reservoir 14 must change direction, velocity,
and travel upwards through the needle as shown by arrow 32 on FIG.
4.
[0029] FIG. 4 illustrates a needle 100 with a single oval opening
33. FIG. 6 shows a needle 100 with two staggered oval openings 33,
36, each for collecting a fraction of the fluid from the cavity 14.
Returning to FIG. 4, the needle is shown in greater detail in FIGS.
5A-5B and includes a pointed tip 62 with an end tip 61 of 0.06 inch
in length in one preferred embodiment. The pointed tip 62 in
another embodiment is a 20.degree. cone. The inside portion of the
cone shown in FIG. 5B includes a bottom resting place 63 shown as a
semicircular surface to help stabilize the inner flow in the needle
100. What is contemplated is the use of a resting place 63 of such
geometry to help with manufacturing while providing the greatest
laminar flow within the main body of the needle 100.
[0030] The use of a vertical oval needle tip allows the creation of
a greater opening surface than a regular or circular hole without
weakening the body of the needle 100 at any portion of the needle
along its vertical axis by not removing any metal in the radial
orientation. FIG. 6 is another configuration where no portion of
the needle 100 is weakened by placing two different openings along
a single longitudinal radius. Two successive openings are staggered
at different radial positions, shown to be at 180 degree or on
opposite side of the needle. FIG. 8 shows a configuration where a
grid of smaller holes 47 can be used and placed in a radial
staggered configuration to draw in blood. In one preferred
embodiment, the smaller holes 47 cannot be made to a size smaller
than 5 to 10 times the total cross-section of 34 .mu.m of the cells
in the blood, or a size of 170 to 340 .mu.m (0.0068 to 0.0136 in.).
In yet another preferred embodiment, the circular opening diameter
is 0.042 inch and is offset from the cone by 0.035 inch.
[0031] These needle configurations with multiple openings can be
flow calibrated either by inserting the needle partly into the port
plenum so only a portion of the openings is in contact with the
blood flow, or by using a partial and movable cover.
[0032] For each of the embodiments shown, the edges of the
different openings are rounded as shown with greater detail as 34
and 35 in FIG. 5A. What is also contemplated is the use of internal
edges to direct the incoming flow in a selected direction to
prevent the formation of vortices within the needle. What is also
contemplated is the use of different walls or separations within
the needle 100 to further direct the flow.
[0033] In one preferred embodiment, the internal diameter (d) of
the needle 100 is taken to be 0.0525 to 0.0545 in. The external
diameter of the needle 100 is taken to be 0.0645 to 0.0655 in. This
corresponds to a minimum passage section of 0.0021 sq. in.
(S=.pi.(d/2).sup.2). The surface of a circular opening of diameter
0.042 in. on the lateral wall of a needle is 0.0014 sq. in.
(S=.pi.(0.042/2).sup.2) but for an oval opening made on a cylinder
having a principal axis of 0.042 in. and a secondary axis of 1.5
times the principal axis 0.063 in., the surface can be approximated
to 0.0021 sq. in. (S=.pi.AB). The use of an opening with a passage
area equal to the passage area of the needle 100 to prevent locally
an increase in velocity in the blood is contemplated. As shown in
FIG. 7, the use of a circular hole 37 placed on a bent needle or
the use of two holes 37, 38 to regulate the flow of fluid through
the needle is also contemplated.
[0034] What is also contemplated is the use of a permanent or a
temporary coating placed on the needle to improve the flow inside
of the needle, such as for example an anti-clouting coating like
heparin, a bio-compatible coat like polished titanium oxide
coatings, or even polymer coating such as, for example, Teflon or
PTFE. In one embodiment, the coating is placed inside of the needle
to facilitate the flow of blood. In another embodiment, the coating
is place at the edges of the openings on the needle to reduce
friction. In yet another embodiment (not shown), a sliding cover in
the shape of a metallic shell can be retracted over a portion or
the totality of the body of the needle. The placement of the cover
allows for the control of the flow and the protection of the
needle. In yet another embodiment, instead of a Huber needle, a
regular needle with a cylindrical entry surface can be used in
tandem with a pull out rod with pointed tip (not shown). In a first
step of a method of use, the pointed rod is pushed passed the tip
of the needle and enters the skin until the external perimeter of
the needle contacts with the outer layer of the skin. The needle is
then pushed in, and finally, the pull out rod is pulled out leaving
the needle in place and allowing the flow of blood in the needle to
start.
[0035] In yet another embodiment, as shown in FIG. 8, an
intermediate portion of the needle can be manufactured of an array
of small rounded strings of metal formed into a cylindrical mesh
for allowing the passage of blood and welded to the end of the
needle in the shape of a Huber tip. In yet another embodiment, the
mesh is not angled and a Huber shape tip is connected to the
mesh.
[0036] What is described is a needle 100 for a subcutaneous port 1
adapted to reduce the damage to the floating particles, such as
blood cells a fluid at the inlet of the needle, the needle 100
having a needle shaft 70 with a bore 75 along a longitudinal axis
of the needle shaft 70 with a proximal end 71 and a distal end 72
in opposition thereof as shown on FIG. 4, a pointed tip 62 at the
distal end 72 with a pointed end tip 61 for the entry of at least a
portion of the needle shaft shown as FIGS. 5A-B into a fluid
reservoir 14 in the subcutaneous port 1. In addition, at least an
inlet orifice or opening 33 along the needle shaft 70 between the
proximal end 71 and the distal end 72 and in fluidic contact as
shown by arrows 31, 32, with the fluid reservoir 14 and adjacent to
the pointed tip 62. The inlet orifice 33 communicates with the bore
75 for the passage of the fluid from the fluid reservoir 14 through
the inlet orifice 33 and through the bore 75 as shown by arrow 32.
Further, the inlet orifice 33 has at least a rounded edge 34 or
35.
[0037] The inlet orifice may be of different shapes as shown
including oval shape as shown on FIG. 4, and where oval shape has a
long axe along the longitudinal axis of the shaft 70. The needle
shaft 70 may have a thickness in the range of 0.001 to 0.003 inch.
While some ranges and dimensions are given, one of ordinary skill
in the art will recognize that any thickness is contemplated. In
the embodiment shown as FIG. 7, the needle shaft 70 along the
longitudinal axis is curved adjacent to the pointed tip 62. The
plurality of orifices 47 or the grid of small holes are along the
needle shaft 70 between the proximal end 71 and the distal end 72
and in fluidic contact with the fluid reservoir 14 and adjacent to
the pointed tip 62, and where each of the plurality of inlet
orifices as shown communicate with the bore 75 for the passage of
fluid as shown by the arrows 31, 32 from the fluid reservoir 14
through the inlet orifice 33 and through the bore 75.
[0038] What is also contemplated is a method of protecting blood
cells from damage during a medical treatment with a subcutaneous
port 1, where blood is circulated through a needle 31, 32, the
method having the steps of connecting (not shown) a needle 100 to a
medical treatment device such as a hemodialysis machine for
conducting a treatment using multiple circulation of blood through
the needle 100, the needle 100 having a needle shaft 70 with a bore
75 along a longitudinal axis shown by the dashed line on FIGS. 4 to
6, and 8 of the needle shaft 70 and a proximal end 71 and a distal
end 72 in opposition thereof, a pointed tip 62 at the distal end 72
with a pointed end tip 61, and at least an inlet orifice 33 along
the needle shaft between the proximal end 71 and the distal end 72,
and where the inlet orifice 33 has at least a rounded edge 34, 35
for the protection of blood cells. In a subsequent step, the plenum
surface 20 as shown on FIG. 6 is punched for entry of at least a
portion of the needle shaft 70 and the inlet orifice 33 into a
fluid reservoir 14 in the subcutaneous port 1. The inlet orifice 33
is then placed in fluidic contact as shown by arrows 31, 41, 42,
and ultimately 32 on FIG. 6 with blood in the fluid reservoir for
the passage of the blood from the fluid reservoir 14 through the
inlet orifice 33 and through the bore 75. Finally, the machine is
then put on for the circulation of the blood so the flow of blood
circulates around the rounded edge 33. In addition, openings are
designed so the flow is not accelerated in the vicinity of the
edges by having a plurality of openings in a single needle.
[0039] It is understood that the preceding is merely a detailed
description of some examples and embodiments of the present
invention and that numerous changes to the disclosed embodiments
can be made in accordance with the disclosure made herein without
departing from the spirit or scope of the invention. The preceding
description, therefore, is not meant to limit the scope of the
invention but to provide sufficient disclosure to one of ordinary
skill in the art to practice the invention without undue
burden.
* * * * *